■ もう V-ました
■ まだ V-て（い）ません
Meaning:
もう V-ました: “have already done”
まだ V-て（い）ません: “have not done yet”
もう + V-ました
まだ + V-ていません
もう is used with completed actions, to confirm or report that something has already happened.
まだ is used with negative forms, to express that something has not happened yet.
For casual speech, ていません becomes てません.
To answer briefly, you can say まだです (Not yet).
■ まだ V-ます
Meaning: “still doing something” / “still ongoing”
まだ can also mean “still”, not just “not yet”.
When used with a positive sentence, it shows that an action or state is continuing.
Commonly used when asking if something is still happening or expressing that something is not over yet.
■ 【Interrogative】＋ S（plain-form）か、～
Meaning:
Do you know [interrogative] + S?” / “Can you tell me [interrogative] + S?
(e.g., “Do you know when/where/what/etc. …?”)
Interrogative word + sentence in plain form + か + main clause
e.g., 何時[なんじ]に 始[はじ]まるか、わかりますか？
Used when embedding a question inside another sentence (e.g., asking if someone knows something).
The embedded question must be in plain form, even if the original sentence would normally end in ですか.
Common interrogatives: 何[なん] (what), どこ (where), だれ (who), いつ (when), どうして (why), どうやって (how)
Common verbs that follow: わかりますか (do you know), 知[し]っていますか (do you know), 教[おし]えてください (please tell me)
Often used when it’s uncertain if the listener knows the answer.